Electrotherapy (TENS/Ultrasound Therapy)

Electrotherapy is a physiotherapy treatment that uses controlled electrical currents or sound-wave energy to reduce pain and help the body heal. The two most common forms are TENS (Transcutaneous Electrical Nerve Stimulation, which delivers mild electrical pulses through the skin) and Ultrasound Therapy (which uses high-frequency sound waves to warm and stimulate tissue deep under the skin).

TENS works by sending gentle electrical signals through small pads placed on the skin. These signals interfere with pain messages travelling to the brain and may also encourage the body to release endorphins (the body's own natural pain-relieving chemicals). Ultrasound Therapy uses a handheld probe that emits sound waves too high-pitched for human hearing. These waves pass safely through the skin and create a gentle warming effect in muscles, tendons (the tough bands connecting muscle to bone), and ligaments (the bands connecting bone to bone), which can ease stiffness, reduce swelling, and support tissue repair.

Electrotherapy is used across a wide range of musculoskeletal (muscle, joint, and bone) and nerve-related conditions. A physiotherapist will assess whether TENS, Ultrasound Therapy, or a combination of both is the most appropriate choice for a particular patient and their specific condition.

• Acute and chronic (long-lasting) back or neck pain
• Osteoarthritis (joint-surface wear and tear) in the knee, hip, or shoulder
• Tendinitis (inflammation of a tendon), such as tennis elbow or Achilles tendinitis
• Sports injuries, including muscle strains and ligament sprains
• Post-surgical rehabilitation to restore movement and reduce pain after an operation
• Frozen shoulder (adhesive capsulitis), where the shoulder joint becomes stiff and painful
• Fibromyalgia (widespread muscle pain and tenderness)
• Carpal tunnel syndrome (nerve compression in the wrist causing hand numbness and pain)
• Bursitis (inflammation of the fluid-filled sacs that cushion joints)
• Scar tissue management after injury or surgery

Electrotherapy is not suitable for everyone. A physiotherapist will carefully screen each patient before starting treatment. It is generally not used in the following situations:

• Over an area where the patient has a pacemaker (an implanted heart-rhythm device) or other active electronic implant
• Directly over a malignant tumour (cancer) area
• During pregnancy, particularly over the abdomen or lower back
• Over open wounds, broken skin, or areas of active infection
• In patients with epilepsy (a seizure disorder), for TENS applied near the head or neck
• Over areas with reduced sensation, where the patient cannot reliably report discomfort
• Directly over metal implants, for therapeutic ultrasound specifically
• In children under the age at which the physiotherapist judges it safe

Electrotherapy is generally considered very safe when performed by a qualified physiotherapist; serious complications are uncommon. The risks below are recognised, with the most frequently reported listed first.

• Skin irritation or redness under the TENS electrode pads, which usually fades quickly after the session ends
• Mild tingling, buzzing, or warming sensation that feels uncomfortable if the intensity is set too high — the physiotherapist adjusts settings to keep this within a comfortable range
• Small skin burn from ultrasound if the probe is held still too long in one spot — therapists keep the probe moving to prevent this
• Allergic reaction to the adhesive (sticky material) on TENS electrode pads, leading to a skin rash in that area
• Temporary increase in local pain or muscle soreness after the first few sessions, which typically settles as treatment continues
• Headache or dizziness on rare occasions, particularly if TENS is applied near the head or neck
• Accidental stimulation of nearby nerves if electrodes are placed incorrectly, causing unexpected muscle twitching

Electrotherapy sessions do not usually require fasting (going without food or drink) and are done on an outpatient basis, meaning the patient goes home the same day. There are no general dietary restrictions before a session. However, it is worth arriving well-rested and hydrated (having had enough water), as this can support comfortable treatment.

Before the first session, the physiotherapist will ask about all current medications, including blood thinners, anti-inflammatory medicines, and any skin creams or patches applied to the treatment area. Patients are usually asked to remove any metal jewellery, piercings, or clothing with metal fasteners from the area to be treated. For ultrasound therapy, a coupling gel (a water-based gel that helps sound waves pass into the skin) will be applied, so loose, easy-to-remove clothing over the treatment area is helpful.

Formal pre-procedure tests such as blood work or imaging are not routinely needed for electrotherapy itself. However, if the physiotherapist has not yet reviewed existing scans or reports about the patient's condition, they may request to see recent X-rays, MRI, or ultrasound images to better understand the area being treated.

A typical electrotherapy session follows these general steps, though the exact sequence may vary between clinics and individual treatment plans:

• 1. Initial assessment: The physiotherapist reviews the patient's history, current pain levels, and any contraindications (reasons the treatment should not be used).
• 2. Positioning: The patient is comfortably positioned — usually sitting or lying down — so the treatment area is accessible and relaxed.
• 3. Skin check: The physiotherapist examines the skin at the treatment site for any cuts, rashes, or irritation that might affect where pads or the probe can be placed.
• 4. For TENS — Electrode pad placement: Self-adhesive pads are placed on or around the painful area. The physiotherapist selects the electrical frequency and intensity that suits the condition being treated.
• 5. For TENS — Session: The device is switched on and the patient feels a mild tingling or buzzing sensation. The intensity may be gradually increased to a comfortable level. The session lasts for the duration the physiotherapist decides is appropriate.
• 6. For Ultrasound Therapy — Gel application: A coupling gel is applied to the skin over the treatment area to allow sound waves to enter the body without interruption.
• 7. For Ultrasound Therapy — Probe movement: The physiotherapist moves the probe in slow, circular or sweeping motions over the area. The patient usually feels gentle warmth. The session length is determined by the size of the area and the therapist's clinical judgment.
• 8. End of session: Pads or gel are removed, the skin is cleaned, and the physiotherapist checks for any immediate skin reaction.
• 9. Feedback: The patient describes what they felt during treatment so the physiotherapist can adjust future sessions accordingly.

Because electrotherapy is non-invasive (nothing enters the body) and does not involve sedation (medicine to make the patient sleepy), recovery is immediate for most people. There is no stay in hospital or formal recovery room observation needed. Patients can usually resume their normal daily activities straight away, unless the physiotherapist advises otherwise based on the underlying condition being treated.

• Skin care: If there is any redness or mild irritation where the TENS pads were placed, the area can be gently rinsed with cool water. Avoid applying heat, tight clothing, or harsh products to irritated skin until it has settled.
• Gel residue: Any coupling gel left from ultrasound therapy can simply be wiped away with a clean cloth or tissue.
• Activity: In most cases, light everyday activity is encouraged right after a session. Strenuous exercise or heavy lifting over the treated area should only be resumed on the physiotherapist's advice, as the underlying condition may limit what is safe.
• Pain response: Some patients notice a temporary increase in soreness in the treated area after the first few sessions. This usually settles within a day or two. If pain significantly worsens or new symptoms appear, the physiotherapist should be informed before the next session.
• Number of sessions: Electrotherapy is almost always part of a course of treatment. The physiotherapist will decide how many sessions are needed and how often, based on how the patient responds. Progress is reassessed regularly.
• Home TENS use: In some cases, a physiotherapist may recommend a portable TENS device for use at home between clinic visits. The physiotherapist will explain the correct settings and placement before the patient uses it independently.
• Follow-up: Regular follow-up appointments allow the physiotherapist to track progress, adjust the treatment approach, and combine electrotherapy with exercises or manual therapy (hands-on physiotherapy techniques) as appropriate.
• Lifestyle support: Patients are usually guided on posture, movement habits, and simple exercises that can support the effects of electrotherapy between sessions and help prevent the problem from returning.